Officials are probing how a 51-year-old highway bridge came to collapse in the Italian port city of Genoa yesterday, killing at least 26 people and injuring 16 others as it sent dozens of vehicles tumbling into a heap of concrete and twisted steel.

Abbott should face court, says prominent lawyer

Human rights advocate and lawyer Julian Burnside has told protesters in Melbourne they can look forward to seeing Tony Abbott in the dock in an international court.

Today's protest against the federal government's policies and budget drew around 10,000 people, although organisers put the figure closer to 20,000.

Mr Burnside criticised the government's policy on refugees.

"The way they are treating refugees in Australia is a crime, and there has already been a reference put into the international criminal court complaining of that very treatment," he said, drawing a cheer from the crowd outside the Victorian Parliament.

"If you feel exhausted keeping up the pressure on the government, if you feel so tired you can't keep going, just support yourselves with the vision of Tony Abbott and Scott Morison in the dock at The Hague."

The crowd also jeered as a large Tony Abbott puppet waved at them with smoke coming from its rear, representing a person with their pants on fire.

Protesters had chanted "We demand better" and "Bust the budget" as they marched through Melbourne's city streets that were closed to vehicles and trams.